By the 1960's Ralph Moore had introduced five species roses into his miniature rose breeding lines -- even before his more recent work with mosses, bracteatas and hulthemias. "The Wizard's Words," Jim Delahanty, American Rose, Jan. 2007, p. 23. [From Gardening with Roses, by Judith McKeon, p. 33:] California hybridizer Ralph Moore is an important contributor to the diversity of miniature roses.

[From The Quest for the Rose, by Roger Phillips and Martyn Rix, p. 226:] Ralph Moore has been in the forefront of the development and popularization of Miniature Roses since 1937... he started growing rose seedlings while still at high school in the 1920s. In 1927 he sowed seeds from a huge plant of 'Climbing Cecile Brunner' in the garden next door. One of the seedlings had tiny white flowers on a bush about 90 cm (3 ft.) tall, but there was little interest in Miniatures at this time and that plant was lost... Ralph Moore first saw Rosa rouletti in 1935. Soon after, he bought plants of 'Tom Thumb', raised by de Vink in the Netherlands, and 'Oakington Ruby', raised by Bloom, and his enthusiasm for Miniatures was rekindled. From these roses, Ralph began the breeding programme that is still going strong today.

[Ibid, p. 228:] Ralph himself describes his rose breeding as a joyful journey and adventure... When we visited him we saw roses with petals like oak leaves, with red eyes, picotee edges and stripes... [an interesting discussion of the various types of roses Moore has crossed with, including Mosses which] led to the first yellow-flowered modern Moss, 'Goldmoss', introduced by Moore in 1972.

[From Miniature Roses: Their Care and Cultivation, by Sean McCann, p. 14: In the UK,] only one company, Gregory's of Nottingham, made miniatures a large part of its production, and it dealt mainly with roses originated in California by Ralph Moore.

[Ibid, p. 132:] It was Ralph Moore who began the interest in single-petalled miniatures when he introduced 'Simplex' in 1961; the five petals are white with a golden centre.